The present invention relates to a recording apparatus with a keyboard, capable of writing characters and plotting graphs on a recording medium with suitable writing imstruments, according to input data keyed in through the keyboard.
A recording apparatus is known, wherein graphs are plotted or drawn on a sheet of paper by relative movements of the sheet of paper and a writing instrument such as a ball-point pen.
Such a known recording apparatus, however, is not capable of writing various characters such as letters, numerals and symbols, by operating the corresponding character keys, and plural fuction keys disposed on a keyboard as provided on an ordinary typewriter.
In view of the above, the assignee of the present application developed a recording apparatus with a keyboard, which is capable of writing characters in a writing mode, and plotting graphs in a plotting mode, according to input data keyed in through the keyboard. This recording apparatus comprises (a) a keyboard having a multiplicity of keys including character keys corresponding to the characters, the keyboard being operable in a first mode in which at least numerals can be keyed in, and in a second mode in which letters and symbols can be keyed in; (b) a paper feeding device for supporting and feeding a sheet of paper in opposite directions; (c) a carriage supporting a writing instrument, and movable in a direction perpendicular to a line of feed of the sheet of paper; and (d) a control device for controlling the operations of the paper feeding device and the carriage, to write with the writing instrument in the writing mode the characters which are keyed in through the character keys, and to plot the graphs with the writing instrument in the plotting mode based on the operations of the multiplicity of keys on the keyboard.
The recording apparatus described above is advantageous in that the keyboard which is selectively placed in the first or second mode permits recording of a large number of different characters in the writing mode. In the plotting mode, however, the need of writing characters is relatively limited. Namely, an ordinary plotting operation in the plotting mode requires the writing of numbers (numerals), and a limited number of symbols such as decimal point.
If the first and second modes are available in the plotting mode as well as in the writing mode, the operator of the apparatus has to pay attention to the previously and currently selected modes of the keyboard and to the mode which will be selected, each time the mode of the apparatus is changed from the writing mode to the plotting mode or vice versa. This is cumbersome to the operator and may reduce the recording efficiency.